The National Institute for Agro-Environmental Sciences (NIAES) announced on August 21, 2009, that they have jointly developed a new phytoremediation method in order to restore contaminated rice paddy fields using rice cultivars that are capable of accumulating cadmium (Cd) at high levels. The joint research contributors included the Yamagata Integrated Agricultural Research Center, the Niigata Agricultural Research Institute, the Fukuoka Agricultural Research Center, the Akita Prefectural Agriculture, Forestry and Fisheries Research Center and Mitsubishi Chemical Corp..

Regarded as a highly promising technology, phytoremediation uses plants that absorb contaminants, such as toxic chemicals, to restore polluted soils. The new method, which involves cultivation of these high Cd-accumulating rice varieties in a contaminated field using a technique to drain irrigation water in the early stages, decreases the Cd concentrations in the soil by 20 to 40 percent. Cd concentrations in the rice grains that are subsequently grown in the field for human consumption can be 40 to 50 percent lower than Cd concentrations in rice cultivated in non-treated fields.

As it requires less water for irrigation and can be practiced using existing agricultural equipment, the new remediation method is cost efficient and practical. In fact, the Japanese Ministry of Agriculture, Forestry and Fisheries already has a demonstration project in progress. If successful, it will become the world's first phytoremediation method to be put to practical use. Furthermore, a collaboration project with researchers overseas is currently being considered; practical application of this phytoremediation method is anticipated in various worldwide regions having Cd-contaminated rice fields.